Turret type slim line lamp holder



ug' 5, 1952 J. M. PlsTEY TURRET TYPE SLIM LINE LAMP HOLDER Filed July 51, 195o Inventor:

His Attorney Patented Aug. 5, 1952 John Pistey, Faireld, Conn.; assig-nor'to .Gpen-y eral- Electric=.Company, a. corporationf-New...

York

Applicit .Ily131, 1950;' SllJN 6.1756329 3 Claims.. (Cl. 173-328).

invention relates -to lamp holders for lamps of the fluorescent or -gas-lledtype and particularlyqto an improved lamp holder and safety features for themounting thereof. f

In modern uorescentlamps "of the gas-filled type, A`it is-commonto have but a lsingle terminal on each end of a lamp. This 'lampisthenput in a circuit with*` a Y'ballast transformer,l usually an autotransformer .which supplies tothe lamp a l'voltagehigher .than the line voltage. With this arrangement, the holder forV one end. ;f the lamp vis called .the high voltage larnpholder and the holder for the other endof the lamp iscalled theY lowlvoltage lampholder. The .latter is cus.- tomarily Yprovided "with a pair Vof contacts Hin series with one .side-.ofthe supply' linefwhich contacts are interconnected :only when a .lamp terminalis inserted into. that holder.

With'installations of the subject type, itis common tov position eachof the lamp holders at a xeddistance apart. One end .of the lamp. is then. first inserted into 'the4 highvoltage lamp holder by pushinglagainsta spring therein to permit` .theother end ofthe lamp ,to beinserted into. position ,in the. low voltage lamph'older..

The spring biased terminal is used for the high voltage end of the,v ,lampholderto .assure that contact .isn'iadeor` that a complete circuit'. is made; across .theloW-.voltage lamp. holder.

In .order to meet. requirements `of the Under- WritersLabQratories, all connecting screws inthe high .voltageend -.of thelamp holder must be .suitablyjinsulated to. be protected. from...any -.con tact With-grounding. material ofthe lamp .holder or. of. surfaces on whichy itA mayfbe mounted.

Whilelamp holders .of the spring biased type have been used for the high .Voltage end, there is stillfneed in the art for an improvedlamp Iholder oithespring biased type thatwill providepositive contact betWeenthe-lampfholder,and one end-oi thelamp, and which will, be rugged and economiycalato.manufacture Itis van vobject otthis invention-to vprovide a newandimproved.. lamp holder vfor uorescent lamps `of the gas-.filled type. Y Y

Itis-a `urtherfoloject of thisinvention .topro- Videa-.new safety. feature .for the mountingm the-high voltage end of a lampholder .which willassure the. insulatingof allconnecting screws therein.

lurther.-.objects and ,advantages :of this .invention will become .apparent andthe invention will bemore clearly understood y:Erorlfithe fol-lowing.y description .referring to the accompanying drawing. and the. features-of novelty` which ,chaine autoriza-.this invention will be pointed Y out with particularityin-the claims annexedlto andi form-3- ingapartoiithis specification;

Briefly, ithis .invention comprises van improved high :voltag'ef lamp .holders whichj is provided with an z insulating cylinder. .and fmovable contact; pi ton ifor each vlamp, andan insulating. safety-fe ture: Vwhichspreve'ntsigthe lproper installatie l f; thelamp .holder until allicon'necting, screws-vare, protected and insulated.. L In :fthe draWing,;fFi'g..-tl is:.a yside.)vieilli-,aparltly. section, :oiga fluorescent lampfinstaliation iorth'e, improved typen Fig.; 2 .is .anifend view-:partly: section, of `the l lamp; holder; :shown: inn-.Figs I and; taken .fthrough ,thei line 2: '2 zin'v the'zdirectio'n off-.the arrows; Figs-.3 .is:.a topviewfpartlwimsec; tion `of the; .high .'voltagefflainp :holden shown4 in Fig.. 2 ;.;while;-Fig.i4 another .viewnf the toprof the lamp` holder vshowntin.:Figo-12 .witlifthe dotted line and solid line.-indicating-twofpositions Lofnthe. insulating strip in theplamp holder.:

Referring. .to the drawing.. a vlamp'installation l 'iismshown .'compris'ingca lamp 2 zinstalledf.. in a high V'wilta'ge holder'x3 fand.. a low-Voltage :holder 4. Thev .lamp f2 fis `provided Withia pair: ofcongi tacting .prongs B'and shown-in engagement. rea, spectively Witha high voltage'conta'ct .platefl` and a'low.voltagescOntactplateB. f

The high voltagek holder d'comprisesfafcasing 9 Which-encases'onexorvmore plastic cylindrical contactV holders'flmtcontact pistons" -l foreach of thefcontactholdera avspringllZ, and .fa con ducting. :b'ar "I3 which' is-connected to fa ballast transformer throughterminal "cirset` Asc'retv'fcona 4.

Eachv ofv the #contact holders lll' -1cylindri cal sectionL of some plasticm'aterialfpro ide'dwitl a plurality 'ot grooves-I'lwliich extend lnst the. complete -axiarlength of the contact holder l0,- .butl which terminate `snort of the outermost portion to act asi.. stops :fori ,sliding. piiitlesfwlS which 'are Vinte'g'rally'cas't with plastic#cont'tctr stons fl I and -which eng"age1thegrooves yi'l f The spring-l2 engages-contact plate I` Wliie is-forliid inthe yplastic :piston contact-'11 l.. Spring'ffl'Z isl under-'compression `between Contact plat 1 'and conducting` bar. I3l to insure good-Aelectricalfcn tact between the .conducting bar- I 3? and-tlicn tact 'l in piston-contact H.' Withthsstructuie; piston contact H' can.`r be movedy infopposltinto the bias of' the fsprin'g. towards-"conducting ai'` I3- to provide.; for. the.: insertion .of .lamp .2 iin-:th'e

lamp: holder.

oasing .is provided ,witnzrafpiurauty-fof-iri-iA 3 dents I9 which are engageable with a corresponding number of openings provided in brackets 2| secured to the cover plate I5. The combination of the indents I9 and the openings 20 with set screw I6 which is engageable with a threaded bore 23 secured in the casing 9 gives :drm three point conta-ct between the cover plate I and the casing 9. Cover plate I5 further defines a pair of openings 24 engageable with the contact holders I0, which, in turn, have a cut-away portion 25 to prevent the contact holders I0 from passing through the cover plate I5.

Conducting bar I3, as shown more particularlyV in Fig. 2, connects the center of spring I2 to an insulating block 26 which is positioned within the casing 9. The insulating block is of substantially the same length as the rear portion 21 of casing 9. Casing 9, in turn, is provided with a pair of indents 28 engageable with a corresponding pair of grooves 29 in the insulating block 26 to allow for the sliding of the insulating block 26 `into or out of the casing 9. vThe insulating block 26 is held by set screw |6, which is in engagement with the threaded bore 23. The combination of the indents 28, the grooves 29, and set screw I6 position l the insulating block 26 in spaced apart relationship from the rear side 30 of the casing 9 to allow for the sliding of an insulating strip 3| between the insulating block 26 and the rear side 30. Insulating strip 3| has, as an integral'part thereof, a portion 32 extending transverse to the rear side 30 and parallel to the bottom 33 of the casing 9. Insulating block 26, in turn, has cast integrally therewith a spacer strip 34 which positions the insulating block 26 above the bottom 33 of the low voltage lamp holder 3. Consequently, portion 32 of insulating strip 3| is free to slide between insulating block 26 and the bottom 33 of casing 9.

Insulating block 26 is further provided with a stop 35 extending away from the insulating block a distance equal to that of spacer strip 34. Insulating strip 3| has formed in its bottom portion 32 an opening 36 engageable with spacer strip 34 and an opening 31 engageable with stop 35. This structure allows for the sliding of insulating strip 3| a fixed distance in one direction or another relative to the insulating block 26.

The conducting bars I3 are secured to insulating block 26 by rivets 38. A plurality of conducting strips 39 Vconnect the rivets 38 to set screws I4, which, in turn, are the connecting screws for connecting the high voltage lamp holder to a ballast transformer (not shown).

Insulating strip 3| further denes a plurality of openings 40 which facilitate the positioning of a screwdriver or similar tool (not shown) in engagement with the set screws I4 to allow for the connecting of conductors to the set screws I4. Insulating strip 3| has as an integral part thereof a pair of extending ears 4I at each end which extend away from and in a plane with the insulating strip 3|. The ears 4|, when openings 36 and 31 of insulating strip 3| are moved into engagement with either side of the spacer strip 3 4 and stop 35 are adapted to cover one of a pair of keyhole slots 42 which are positioned in the rear side 30 of casing 9 to provide for the positioning of the high voltage lamp holder on a supporting structure of some kind.

The openings 40 and the ears 4I are so positioned in relation tothe keyhole slots 42 and the stop 35 that one of the keyhole slots 42 is covered by one of the ears 4| if one of the set screws I4 is exposed. Specifically, in order to secure the high voltage lamp holder 3 to any supporting structure by means of the keyhole slots 42, it is necessary that the insulating strip 3| be positioned between the keyhole slots 42. When this is done, the ears 4| expose the keyhole slots 42 and, at the same time, the insulating strip 3|, because of the positioning of the openings 40, covers the set screws I4.

This is particularly shown in Fig. 3 where the set screws I4 are indicated by dotted lines as being behind the insulating strip 3| when the ears 4| arepositioned between the keyhole slots Fig. 4, on the other hand, indicates that the righthand ear 4I should be positioned to cover the corresponding keyhole slot 42 in order to expose one of the set screws 4 and that the strip 3| must then be positioned with the opposite ear 4| in engagement with the opposite keyhole slot 42 in order to expose the other set screw 4| for connection to a conductor leading to a ballast transformer. With this structure. the insulating strip 3| covers the set screws I4 in order to allow for high voltage holder 3 to be installed on some supporting structure by means of keyhole slots 42. Consequently, the Underwriters Laboratories, Inc. specifications are met with this simple and unique construction.

Modifications of this invention will occur to those skilled in the art and it is desired to be understood, therefore, that this invention is not to be limited to the particular embodiment disclosed, but that the appended claims are meant to cover all the modifications which are within the spirit and scope of this invention.

What I claim as new and desire to secure Letters Patent of the United States is:

1. An improved lamp holder for a gas-filled lamp of thev type having electrical contacting prongs on each end thereof comprising. a casing defining a cavity and a plurality of mounting holes, a cover plate cooperating with said casing to substantially enclose said cavity, a cylindrical insulating contact holder having a recessed outer edge, said cover plate defining an opening engageable with said recessed outer edge to position said insulating contact holder in said cavity, an insulating contact piston including an electrical contact axially slideable in said contact holder, stop means for limiting the movement of said contacting piston relative to said contact holder, a coil spring biasing said contact piston towards the outer edge of said contact holder, terminal screw means positioned in saidcasing to connect said lampholder in an electrical circuit, and electrical conducting means including said spring for connecting said contact piston to said terminal screw means.

2. An improved lamp holder for a gas-filled lamp of the type having electrical contacting prongs on each end thereof comprising, a casing defining a cavity and a plurality of mounting holes, a cover plate cooperating with said casing to substantially enclose said cavity, a cylindrical insulating contact holder having a recessed outer edge,l said cover plate defining an opening engageable with said recessed outer edge to position said insulating contact holder in said cavity, an insulating contact piston including an electrical contact axially slideable in said contact holder, stop means for limiting the movement of said contacting piston relative to said contact holder, a coil spring biasing said contact piston towards the outer edge of said contact holder, terminal screw means positioned in said casing to connect said lampholder in an electrical circuit within said cavity, electrical conducting means including said spring for connecting said contact piston to said terminal screw means, a slideable insulating strip to insulate said terminal screw means and defining an opening giving tool access to said terminal screw means, and a plurality of ears on said insulating strip slideable with said strip to cover one of said mounting holes when said terminal screw means is exposed.

3. An improved lamp holder for a gas-lilled lamp of the type having electrical contacting prongs on each end thereof comprising, a casing defining a cavity. a plurality of mounting holes,

Vwith spring biased electrical contacting means positioned within said case to be engageable with the prongs of a lamp, terminal screw means positioned in said casing to connect said lampholder in an electrical circuit, electrical conducting means conneeting said terminal screw means with said contacting means, a slideable insulating strip including means for positioning the same on said casing for insulating said terminal screw means, said strip defining openings giving tool access to said terminal screw means. a plurality of ears on said insulating strip slideable with said strip to cover one of said mounting holes when said terminal screw means is exposed and to expose all of said mounting holes when said connecting screw means is insulated by a solid portion of said insulating strip.

JOHN M. PISTEY.

REFERENCES CITEp The following references are of record in the file of this patent:

STATES PATENTS Number Name Date 2,285,175 Sparling June 2, 1942 2,288,939 Curtis July 7, 1942 2,399,501 Mueller Apr. 30, 1946 2,487,467 Naysmith Nov. 8, 1949 2.501.485 Tuck 1 Mar. 21,y 1950 

